WordPress Like button (2 posts)

Ive installed the jetpack plugin and activated the sharing option. I have all of the social media buttons suchs as facebook, g+, twitter but i would like to have the WordPress like button also where other wordpress bloggers wich are loged in can like my posts. the thing is that ive search on the internet about this like buton and it seems its available only on wordpress.com version BUT ive seen a lot of self hosted blogs wich have this like button, also there is an option wich you can check on self hosted blogs, right on sharing menu, OPTION that i dont have it.can some1 help me with an advice or something? thanks in advance

Generally, you will find .com allows use of only specific plugins and themes, while .org is wide open...also, are you assuming the sites with the wp like button are not actually hosted on .com? Now, anyone can use .com with their own domain (for a fee).